Azlactone telechelic polymer

ABSTRACT

A curable composition is described comprising a Michael donor component, a polyacryl component, and 1) an ethylenically unsaturated monomer having a reactive azlactone functional group, or 2) an ethylenically unsaturated monomer having a reactive ring-opened azlactone functional group. A telechelic polymer that is the reaction product of these components is also described.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. Ser. No. 10/957,356, filed Oct.1, 2004, now allowed, the disclosure of which is incorporated byreference in its entirety herein.

FIELD OF THE INVENTION

The present invention is directed to telechelic polymers havingazlactone or ring-opened azlactone terminal groups.

BACKGROUND

The chemistry of acetoacetate compounds, and the Michael addition toacrylates has been described. For example, Mozner and Rheinbergerreported the Michael addition of acetoacetates having a β-dicarbonylgroup to triacrylates and tetracrylates to form gel products. SeeMacromolecular Rapid Communications 16 135-138 (1995).

U.S. Pat. No. 6,025,410 notes that the stoichiometry of the Michaeldonor to the Michael acceptor is critical to controlling the molecularweight. The reference teaches that certain soluble liquid uncrosslinkedoligomers, made by one step Michael addition of acetoacetates tomulti-acrylates, can be further crosslinked using ultraviolet lightwithout using photoinitiators. If proportions below the claimed rangesare used, crosslinked gels or solid products are made which are notuseful because only un-gelled, uncrosslinked liquid oligomers willfurther crosslink without adding photoinitiators. The described liquidoligomer compositions, since they are liquids, can readily be applied tovarious substrates using conventional coating techniques such as roll orspray prior to ultraviolet light cure.

U.S. Pat. No. 5,132,367 describes NCO-free resins and cured productsthereof. The cured products are obtained by a Michael reaction of anacetoacetylated (meth)acrylic resin or an acetoacetylated polyester andan NCO-free polyurethane having at least two (meth)acrylic end groups.U.S. Pat. No. 5,132,367 however does not teach the use of these productsin electrical applications.

EP 227454 discloses a process for preparing a cured polymer involvingthe Michael reaction of an acetoacetylated polyol and a polyα,β-unsaturated ester. The obtained cured products are said to exhibitexcellent adhesion, excellent solvent resistance, excellent glossretention, good flexibility and hardness.

U.S. Pat. No. 5,459,178 describes mixtures comprising an acetoacetateester, an α,β-ethylenically unsaturated monomer and a liquid tertiaryamine catalyst. A cured system is obtained by reacting these components.The acetoacetate ester used is prepared by transesterification ofpolyhydroxyl compound having an average of at least two hydroxy groupswith an alkylacetoacetate.

U.S. Pat. No. 4,871,822 discloses a Michael reaction of olefinicallyunsaturated compounds with compounds containing at least two activehydrogen atoms for 2 component lacquers. As olefinically unsaturatedcompounds there are considered compounds having at least twoα,β-unsaturated carbonyl groups. There are a large number of Michaeldonors including acetoacetylated polyols or polyamines and suchcompounds as e.g. acetylacetone or benzoylacetone.

David L. Trumbo in Polymer Bulletin 26, pages 265-270 (1991) disclosesMichael addition polymers obtained from 1,4- and 1,3-benzenedimethanoldiacetoacetates and tripropylene glycol diacrylate. The referencedescribes that in case the reactants are used in stoichiometric amountsof the reactive groups, gelation of the system is observed. In anotherpaper (Polymer Bulletin 26, pages 481-485 (1991)) the same authordescribed Michael addition polymers obtained from the reaction of abis(acetoacetyl) amide or an aliphatic acetoacetate and a di-acrylatecomonomer. However, no utilisation or properties of the polymers aredescribed in these articles.

WO 95/16749 describes a water-borne curable composition that comprisesan acetoacetylated polymer in the form of an aqueous solution,dispersion or emulsion and a polyacrylate that has at least two(meth)acrylate end groups. According to this publication, suchcomposition is stable even in the presence of a catalyst until the wateris evaporated from the system.

The use of acetoacetyl chemistry, in particular the use ofacetoacetylated resin, in thermosetting systems is further described inJournal of Coatings Technology Vol. 61 no. 771 page 31 to 37; Journal ofCoatings Technology Vol. 65 no. 821 page 63 to 69; Surface CoatingsAustralia, September 1989 page 6 to 15; and Journal of CoatingsTechnology Vol. 61 no. 770 page 83 to 91.

SUMMARY

The present invention provides a curable composition comprising aMichael donor component, a polyacryl component, and 1) an ethylenicallyunsaturated monomer having a reactive azlactone functional group, or 2)an ethylenically unsaturated monomer having a reactive ring-openedazlactone functional group. In another aspect, the invention provides atelechelic polymer that is the reaction product of these components.

In another aspect, the invention provides a method for preparing atelechelic polymer of controlled molecular weight by reacting a Michaeldonor component, a polyacryl component, and 1) an ethylenicallyunsaturated monomer having a reactive azlactone functional group, or 2)an ethylenically unsaturated monomer having a reactive ring-openedazlactone functional group. The invention overcomes the problems in theart by using a mono-ethylenically unsaturated monomer to regulate andcontrol the molecular weight of the resulting polymers and to render thepolymer telechelic. Thus the product polymer has at least one terminalgroup that may be used for further functionalization.

In some embodiments, curable compositions according to the presentinvention are coated on a substrate and at least partially polymerizedto form a protective coating. Accordingly, in another aspect, thepresent invention provides a composite article comprising a substratehaving thereon a coating preparable by at least partially polymerizingthe curable composition.

As used herein:

“acryl” is used in a generic sense and mean not only derivatives ofacrylic acid, but also amine, thiol and alcohol derivatives,respectively;

“alkyl” and “alkylene” mean the monovalent and divalent residuesremaining after removal of one and two hydrogen atoms, respectively,from a linear or branched chain hydrocarbon having 1 to 20 carbon atoms;

“lower alkyl’ means C₁ to C₄ alkyl;

“aryl” and “arylene” mean the monovalent and divalent residues remainingafter removal of one and two hydrogen atoms, respectively, from anaromatic compound (single ring and multi- and fused-rings) having 5 to12 ring atoms and includes substituted aromatics such as lower alkaryland aralkyl, lower alkoxy, N,N-di(lower alkyl)amino, nitro, cyano, halo,and lower alkyl carboxylic ester, wherein “lower” means C₁ to C₄.

“cycloalkyl” and “cycloalkylene” mean the monovalent and divalentresidues remaining after removal of one and two hydrogen atoms,respectively, from a cyclic hydrocarbon having 3 to 12 carbon atoms;

“curable” means that a coatable material can be transformed into asolid, substantially non-flowing material by means of cooling (tosolidity hot melts), heating (to dry and solidify materials in asolvent), chemical cross linking, radiation crosslinking, or the like.

“(meth)acryl” includes both acryl and methacryl groups.

“polyacryl” means a compound having two or more acryl groups that mayfunction as Michael acceptors.

DETAILED DESCRIPTION

The present invention provides a curable composition comprising aMichael donor component, a polyacryl component, and 1) an ethylenicallyunsaturated monomer having a reactive azlactone functional group, or 2)an ethylenically unsaturated monomer having a reactive ring-openedazlactone functional group.

A Michael donor preferably corresponds to one of formulas (I) to (III):

(W¹—CHR¹—C(O))_(x)—P  (I)

(W¹—NH—C(O))_(x)—P  (II)

W¹—CH₂—W²  (III)

wherein

R¹ represents hydrogen, an alkyl group or an aryl group; W¹ and W² eachindependently selected from a cyano group, a nitro group, an alkylcarbonyl group, an alkoxy carbonyl group, an aryl carbonyl group, anaryloxy carbonyl group, an amido group, a sulphonyl group; P representsa mono- or multi-valent organic residue, or the reaction residue of apolyol or polyamine in an acetoacetylation reaction, and

x represents an integer of 1 or more when R¹ is hydrogen, and x is twoor more when R¹ represents an alkyl group or an aryl group. Thus thenumber of donor group equivalents for each of the compounds of FormulasI, II and III is two or greater.

One useful class of Michael donors according to formula (I) areacetoacetylated polyols, which may be represented by Formula I where Pis the residue of a polyol. The acetoacetylated polyol can be preparedby transesterification with an alkyl acetoacetate. A preferredtransesterification reagent for this purpose is tert-butyl acetoacetatedescribed by J. S. Witzeman and W. D. Nottingham in J. Org. Chem., 1991,(56), pp. 1713-1718. The polyols being acetoacetylated in this inventionpreferably have two or more hydroxy groups. The conversion of hydroxygroups to acetoacetate groups should be between 80 mol % and 100 mol %and more preferably between 85 mol % and 100%. Suitable acetoacetylatedpolyols are, for example, those obtained from one of the followingpolyols: polyethylene glycol, polypropylene glycol, polybutylene glycol,pentaerythritol, trimethylolethane, trimethylol propane, bis-trimethylolpropane, K 55™ (available from Bayer AG) which is a condensation productof trimethylolpropane and propyleneoxide, dipentaerythritol, castor oil,glycerine, dipropyleneglycol,N,N,N′N′-tetrakis(2-hydroxypropyl)ethylendiamine, neopentylglycol,propanediol, butanediol, diethyleneglycol and the like. One or more ofthe hydroxyl end groups of such polyols may be acetoacetylated. In someembodiments it may be advantageous to acetoacetylate one end group, andto functionalize the other groups with an ethylenically unsaturatedpolymerizable group, such as an allyl group, a vinyl group or a(meth)acrylate group.

Where a hydrophilic telechelic polymer is desired, a acetoacetylatedpoly(alkylene oxide) may be used. The functional groups terminating thepoly(alkylene oxide) may include hydroxy groups, and amine groups, whichmay be acetoacetylated as previously described. Poly(ethylene oxide),poly(propylene oxide), poly(ethylene oxide-propylene oxide), andcombinations thereof may be acetoacetylated at one or both terminalends.

Lower functionalized acetoacetylated polyols allow a more selective andbetter control of cross-linking than higher functionalizedacetoacetylated polyols. Preferably, an acetoacetylated polyol inconnection with this invention has an equivalent weight of less than 200g/mol. A preferred range of equivalent weight of an acetoacetylatedpolyol in connection with this invention is between 30 g/mol and 5000g/mol.

Examples of Michael donors according to formula (II) are e.g. compoundsof the type p-CH₃C₆H₄—SO₂NHCO₂—P′ wherein P′ represents the residue of apolyol such as e.g. pentaerythritol, trimethylolpropane, 1,6-hexanediol,ditrimethylolpropane, propanediol, diethyleneglycol and the like.

Examples of compounds according to formula (III) are NC—CH₂—CN,CH₃SO₂CH₂CN, CF₃—C(O)—CH₂—C(O)—CF₃, CF₃—C(O)—CH₂—C(O)—OC₂H₅,p-CH₃C₆H₄SO₂CH₂SO₂CH₃, C₆H₅—C(O)—CH₂—SO₂CH₃, (CH₃O₂CCH₂)₂SO₂,p-O₂NC₆H₄CH₂CN, and the like. Further examples may be found in U.S. Pat.No. 5,256,473.

With respect to Formulas I, II, and III, any of P, W¹ or W² may befurther substituted with an ethylenically unsaturated polymerizablegroup, such as a methacryl group, a vinyl groups or an allyl group.Where such groups are unreactive in a Michael addition, they may besubsequently free-radically polymerized, in the presence of a freeradical catalyst. For example W¹ (or W²) may be—C(O)—O—C_(n)H_(2n)—O—C(O)—C(CH₃)═CH₂, —C(O)—O—C_(n)H_(2n)—O—CH₂—CH═CH₂,or —C(O)—O—C_(n)H_(2n)—O—CH═CH₂, where n=1−10. Similarly, P may besubstituted with —C(O)—O—C_(n)H_(2n)—O—C(O)—C(CH₃)═CH₂,—C(O)—O—C_(n)H_(2n)—O—CH₂—CH═CH₂, —C(O)—O—C_(n)H_(2n)—O—CH═CH₂,—O—C_(n)H_(2n)—O—C(O)—C(CH₃)═CH₂, —O—C_(n)H_(2n)—O—CH₂—CH═CH₂, or—O—C_(n)H_(2n)—O—CH═CH₂, where n=1−10.

Useful Michael donors that may be further substituted with anethylenically unsaturated polymerizable group include2-acetoacetoxyethyl methacrylate, and allyl acetoacetate.

A particularly preferred type of Michael donor corresponding to formula(III) for use in this invention corresponds to the following formula(IV):

R²—C(O)—CH₂—C(O)—R;  (IV)

wherein R² and R³; each independently represent an aryloxy group, analkoxy group, an alkyl group or an aryl group.

A Michael donor according to formula (III) and in particular formula(IV) are preferred because they are generally less costly than e.g. anacetoacetylated polyol which requires an acetoacetylation of a polyol asdescribed above. Moreover, this acetoacetylation involves atransesterification during which an alcohol is formed as a waste.Preferred Michael donors according to formula (IV) are those wherein R²and R³; are independently selected from a alkyl such as e.g. methyl,ethyl, propyl, an aryl such as e.g. a phenyl, a alkoxy group such ase.g. a methoxy, an ethoxy, a t-butoxy or a aryloxy group such as e.g. aphenoxy group. Examples of compounds according to formula (IV) areacetylacetone, methylacetoacetate, ethylacetoacetate, methyl malonate,ethyl malonate, t-butyl acetoacetate, and the like.

Useful polyacryl compounds include those of the general formula:

R⁴-(Z-C(O)—CH═CH₂)_(z)  (V)

wherein each Z independently represents —S—, —O—, —NH—, or —NR⁵—, whereeach R⁵ independently represents H, an alkyl group having from 1 to 6carbon atoms;

Each R⁴ independently represents a polyvalent organic group having avalence of z, which can be cyclic, branched, or linear, aliphatic,aromatic, or heterocyclic, having carbon, hydrogen, nitrogen,nonperoxidic oxygen, sulfur, or phosphorus atoms;

each z independently represents an integer greater than or equal to 2.

In one embodiment, R⁴ may be a polyvalent organic group having a valenceof at least 3. Examples of polyvalent groups R⁴ include2,2-bis(ylomethyl)butan-1-yl; ethylene;2,2-bis(ylomethyl)-propan-1,3-diyl; and2,2,6,6-tetrakis(ylomethyl)-4-oxaheptan-1,7-diyl; butan-1,3-diyl;hexane-1,6-diyl; and 1,4-bis(ylomethyl)cyclohexane. Further detailsregarding the R⁴ groups may be had with reference to the followinguseful polyacyl compounds.

Useful polyacryl compounds include, for example, acrylate monomersselected from the group consisting of (a) diacryl containing compoundssuch as 1,3-butylene glycol diacrylate, 1,4-butanediol diacrylate,1,6-hexanediol diacrylate, ethylene glycol diacrylate, alkoxylatedaliphatic diacrylate, alkoxylated cyclohexane dimethanol diacrylate,alkoxylated hexanediol diacrylate, alkoxylated neopentyl glycoldiacrylate, caprolactone modified neopentylglycol hydroxypivalatediacrylate, cyclohexanedimethanol diacrylate, diethylene glycoldiacrylate, dipropylene glycol diacrylate, bisphenol-A diacrylate,ethoxylated bisphenol-A diacrylate, hydroxypivalaldehyde modifiedtrimethylolpropane diacrylate, neopentyl glycol diacrylate, polyethyleneglycol diacrylate, propoxylated neopentyl glycol diacrylate,tetraethylene glycol diacrylate, tricyclodecanedimethanol diacrylate,triethylene glycol diacrylate, tripropylene glycol diacrylate; (b)triacryl containing compounds such as glycerol triacrylate, ethoxylatedtriacrylates (e.g., ethoxylated trimethylolpropane triacrylate,pentaerythritol triacrylate, propoxylated triacrylates (e.g.,propoxylated glyceryl triacrylate, propoxylated trimethylolpropanetriacrylate, tris(2-hydroxyethyl)isocyanurate triacrylate; (c) higherfunctionality acryl-containing compounds such as ditrimethylolpropanetetraacrylate, dipentaerythritol pentaacrylate, ethoxylatedpentaerythritol tetraacrylate, pentaerythritol tetraacrylate,caprolactone modified dipentaerythritol hexaacrylate; (d) oligomericacryl compounds such as, for example, urethane acrylates, polyesteracrylates, epoxy acrylates; polyacrylamide analogues of the foregoing;and combinations thereof.

Such compounds available from vendors such as, for example, SartomerCompany, Exton, Pa.; UCB Chemicals Corporation, Smyrna, Ga.; and AldrichChemical Company, Milwaukee, Wis. Additional useful acrylate materialsinclude hydantoin moiety-containing polyacrylates, for example, asdescribed in U.S. Pat. No. 4,262,072 (Wendling et al.).

Other useful polyacryl compounds also include, for example,free-radically polymerizable acrylate oligomers and polymers havingpendant (meth)acryl groups wherein at least two of the (meth)acrylgroups is an acryl group.

Useful acrylate oligomers include acrylated polyether and polyesteroligomers. Where a hydrophilic telechelic polymer is desired, a polyacylpoly(alkylene oxide) may be used. The functional groups terminating thepoly(alkylene oxide) may include hydroxy groups, and amine groups, whichmay be acrylated. Poly(ethylene oxide), poly(propylene oxide),poly(ethylene oxide-propylene oxide), and combinations thereof may beacrylated at one or both terminal ends.

Useful acrylated polyether oligomers include polyethylene glycoldiacrylates available, for example, under the trade designations “SR259”and “SR344” from Sartomer Company. Acrylated polyester oligomers areavailable, for example, under the trade designations “EBECRYL 657” and“EBECRYL 830” from UCB Chemicals Corporation.

Other useful acrylate oligomers include acrylated epoxies, for example,diacrylated esters of epoxy-functional materials (e.g., diacrylatedesters of bisphenol A epoxy-functional material) and acrylatedurethanes. Useful acrylated epoxies include, for example, acrylatedepoxies available under the trade designations “EBECRYL 3500”, “EBECRYL3600”, “EBECRYL 3700”, and “EBECRYL 3720” from UCB ChemicalsCorporation. Useful acrylated urethanes include, for example, acrylatedurethanes available under the trade designations “EBECRYL 270”, “EBECRYL1290”, “EBECRYL 8301”, and “EBECRYL 8804” from UCB ChemicalsCorporation.

With respect to the useful polyacryl compounds presented above, it willbe understood that the corresponding amides or thioesters are alsouseful. Preferably, the multifunctional ethylenically unsaturated esterof acrylic acid is a nonpolyethereal multifunctional ethylenicallyunsaturated ester of acrylic acid.

The multifunctional ethylenically unsaturated monomer is preferably anester of acrylic acid. It is more preferably selected from the groupconsisting of a difunctional ethylenically unsaturated ester of acrylic,a trifunctional ethylenically unsaturated ester of acrylic, atetrafunctional ethylenically unsaturated ester of acrylic, and acombination thereof. Of these, difunctional and trifunctionalethylenically unsaturated esters of acrylic acid are more preferred.

Preferred multifunctional ethylenically unsaturated esters of acrylicacid and can be described by the formula:

wherein R⁴ is a polyvalent organic group, which can be cyclic, branched,or linear, aliphatic, aromatic, or heterocyclic, having carbon,hydrogen, nitrogen, nonperoxidic oxygen, sulfur, or phosphorus atoms. R⁴may have a molecular weight of greater than 14, and up to 1000;

z is an integer designating the number of acrylic groups in the esterand z has a value of 2-6 (more preferably a has a value of 2-5, mostpreferably 2, or where a mixture of polyacrylates are used, z has anaverage value of about 2).

Examples of suitable multifunctional ethylenically unsaturated esters ofacrylic acid are the polyacrylic acid or polymethacrylic acid esters ofpolyhydric alcohols including, for example, the diacrylic acid anddimethylacrylic acid ester of aliphatic diols such as ethyleneglycol,triethyleneglycol, 2,2-dimethyl-1,3-propanediol, 1,3-cyclopentanediol,1-ethoxy-2,3-propanediol, 2-methyl-2,4-pentanediol, 1,4-cyclohexanediol,1,6-hexamethylenediol, 1,2-cyclohexanediol, 1,6-cyclohexanedimethanol;the triacrylic acid esters of aliphatic triols such as glycerin,1,2,3-propanetrimethanol, 1,2,4-butanetriol, 1,2,5-pentanetriol,1,3,6-hexanetriol, and 1,5,10-decanetriol; the triacrylic acid esters oftris(hydroxyethyl) isocyanurate; the tetraacrylic acid esters ofaliphatic triols, such as 1,2,3,4-butanetetrol,1,1,2,2-tetramethylolethane, 1,1,3,3-tetramethylolpropane, andpentaerythritol tetraacrylate; the pentaacrylic acid andpentamethacrylic acid esters of aliphatic pentols such as adonitol; thehexaacrylic acid esters of hexanols such as sorbitol anddipentaerythritol; the di acrylic acid esters of aromatic diols such asresorcinol, pyrocatechol, bisphenol A, and bis(2-hydroxyethyl)phthalate; the triacrylic acid ester of aromatic triols such aspyrogallol, phloroglucinol, and 2-phenyl-2,2-methylolethanol; and thehexaacrylic acid esters of dihydroxy ethyl hydantoin; and mixturesthereof.

There is a differential reactivity between acryl and methacryl groupswith respect to Michael-type addition. Michael-type addition typicallyoccurs easily with acryl groups (e.g., mere combination of a reactivefluorinated polyether with a compound having an acryl group, optionallywith mild heating, typically, although not necessarily, results inspontaneous Michael-type addition), but may occur only with difficultyif at all, in the case of methacryl groups. For this reason, thepolyacryl component typically has at least two acryl group (e.g., aspart of acryloxy or acrylamido functionality), although thepoly(meth)acryl compound may also have additional (meth)acryl groups(e.g., as part of methacrylate or methacrylamido functionality).Advantageously, composition may be prepared in which Michael additionoccurs through the acryl groups, leaving methacyl groups unreacted. Suchunreacted methacryl groups may be subsequently free-radicallypolymerized.

The functional monomers provide two benefits to the polymers preparedfrom the curable composition: control of molecular weight andincorporation of a functional group on the terminus of the polymer.Heretofore, the molecular weights of polymers derived from acetoacetatesand diacrylates, were controlled by the stoichiometry of one of thecomponents.

Useful azlactone functional monomers may be represented by the formulas:

or ring-opened azlactone monomers of the formula

where

-   R⁵ is H or a C₁ to C₃ alkyl group, preferably H or a methyl group;-   each R⁶ is independently H, an alkyl group having 1 to 14 carbon    atoms, a cycloalkyl group having 3 to 14 carbon atoms, an aryl group    having 5 to 12 ring atoms, an arenyl group having 6 to 26 carbon and    0 to 3 S, N, and nonperoxidic O heteroatoms, or R² and R³ taken    together with the carbon to which they are attached form a    carbocyclic ring containing 4 to 12 ring atoms;-   n is 0 or 1; and

R⁷ is an organic or inorganic moiety and is the residue of a mono- orpolyfunctional compound of the formula R⁷-ZH;

Representative azlactone group-substituted functional monomers include2-ethenyl-1,3-oxazolin-5-one; 2-ethenyl-4-methyl-1,3-oxazolin-5-one;2-isopropenyl-1,3-oxazolin-5-one;2-isopropenyl-4-methyl-1,3-oxazolin-5-one;2-ethenyl-4,4-dimethyl-1,3-oxazolin-5-one;2-isopropenyl-4,4-dimethyl-1,3-oxazolin-5-one;2-ethenyl-4-methyl-4-ethyl-1,3-oxazolin-5-one;2-isopropenyl-3-oxa-1-aza[4.5]spirodec-1-ene-4-one;2-ethenyl-5,6-dihydro-4H-1,3-oxazin-6-one;2-ethenyl-4,5,6,7-tetrahydro-1,3-oxazepin-7-one;2-isopropenyl-5,6-dihydro-5,5-di(2-methylphenyl)-4H-1,3-oxazin-6-one;2-acryloyloxy-1,3-oxazolin-5-one;2-(2-acryloyloxy)ethyl-4,4-dimethyl-1,3-oxazolin-5-one;2-ethenyl-4,5-dihydro-6H-1,3-oxazin-6-one, and2-ethenyl-4,5-dihydro-4,4-dimethyl-6H-1,3-oxazin-6-one.

Representative oxazolinyl group-substituted functional monomers include2-vinyl-2-oxazoline, 2-isopropenyl-2-oxazoline,2-(5-hexenyl)-2-oxazoline, 2-acryloxy-2-oxazoline,2-(4-acryloxyphenyl)-2-oxazoline, and 2-methacryloxy-2-oxazoline.

Ring-opened azlactone compounds of Formula VIII may be made bynucleophilic addition of a compound of the formula R⁷-ZH to theazlactone carbonyl of Formula VII as shown below. In the Scheme II, R⁷is an inorganic or organic group having a nucleophilic -ZH group, whichare capable of reacting with the azlactone moiety of Formula I. R⁷-ZHmay be water.

If organic, R⁷ may be a polymeric or non-polymeric organic group thathas a valence of m and is the residue of a nucleophilicgroup-substituted compound, R⁷-ZH in which Z is —O—, —S—, or —NR whereinR⁸ can be a H, an alkyl, a cycloalkyl or aryl, a heterocyclic group, anarenyl. The organic moiety R⁷ is preferably selected from mono- andpolyvalent hydrocarbyl (i.e., aliphatic and aryl compounds having 1 to30 carbon atoms and optionally zero to four heteroatoms of oxygen,nitrogen or sulfur), polyolefin, polyoxyalkylene, polyester, polyolefin,poly(meth)acrylate, or polysiloxane backbones. If inorganic, R⁷ maycomprise silica, alumina or glass having one or a plurality of -ZHgroups on the surface.

In one embodiment, R⁷ comprises a non-polymeric aliphatic,cycloaliphatic, aromatic or alkyl-substituted aromatic moiety havingfrom 1 to 30 carbon atoms. In another embodiment, R⁷ comprises apolyoxyalkylene, polyester, polyolefin, poly(meth)acrylate, polystyreneor polysiloxane polymer having pendent or terminal reactive -ZH groups.Useful polymers include, for example, hydroxyl, thiol or aminoterminated polyethylenes or polypropylenes, hydroxyl, thiol or aminoterminated poly(alkylene oxides) and poly(meth)acylates having pendantreactive functional groups, such as hydroxyethyl methacrylate polymersand copolymers.

Depending on the nature of the functional group(s) of R⁷-ZH, a catalystmay be added to effect the condensation reaction. Normally, primaryamine groups do not require catalysts to achieve an effective rate. Acidcatalysts such as trifluoroacetic, ethanesulfonic, and toluenesulfonicacids are effective with hydroxyl groups and secondary amines. Basiccatalysts such as DBU (1,8-diazabicyclo[5.4.0]undec-7-ene) and DBN(1,5-diazabicyclo[4.3.0]non-5-ene) are also effective.

Useful alcohols of the formula R⁷-ZH include aliphatic and aromaticmonoalcohols and polyols. Useful monoalcohols include methanol, ethanol,octanol, decanol, hydroxyethyl methacrylate and phenol.

Useful amines of the formula R⁷-ZH include aliphatic and aromaticmonoamines. Any primary or secondary amine may be employed, althoughprimary amines are preferred to secondary amines. Useful monoaminesinclude, for example, methyl-, ethyl-, propyl-, hexyl-, octyl, dodecyl-,dimethyl-, methyl ethyl-, and aniline.

Useful thiols of the formula R⁷-ZH include aliphatic and aromaticmonothiols. Useful alkyl thiols include methyl, ethyl and butyl thiol,as well as 2-mercaptoethanol, 3-mercapto-1,2-propanediol,4-mercaptobutanol, mercaptoundecanol, 2-mercaptoethylamine,2,3-dimercaptopropanol, 3-mercaptopropyltrimethoxysilane,2-chloroethanethiol, 2-amino-3-mercaptopropionic acid, dodecylmercaptan, thiophenol, 2-mercaptoethyl ether, and pentaerythritoltetrathioglycolate. Useful soluble, high molecular weight thiolsincludes compounds such as the adduct of 2-mercaptoethylamine andcaprolactam.

In another embodiment, the compound R⁷-ZH may comprise a solid supporthaving a plurality of -Z-H moieties on the surface thereof. Suchfunctionalized supports have the general structure:

wherein Y—S, R⁵, R⁶, Z, and n are as previously described for Formula IIand SS is a solid support corresponding to R⁷ having a plurality ofnucleophilic -Z-H groups on the surface thereof. The solid supportmaterial includes functional groups to which molecules of Formula IX canbe covalently attached for building telechelic polymers on the surface.Useful functional groups include hydroxyl, amino and thiol functionalgroups corresponding to -ZH.

The support material can be organic or inorganic. It can be in the formof solids, gels, glasses, etc. It can be in the form of a plurality ofparticles (e.g., beads, pellets, or microspheres), fibers, a membrane(e.g., sheet or film), a disc, a ring, a tube, or a rod, for example.Preferably, it is in the form of a plurality of particles or a membrane.It can be swellable or non-swellable and porous or nonporous.

The support material can be a polymeric material that can be used inconventional solid phase synthesis. It is chosen such that it isgenerally insoluble in the solvents or other components used insynthetic reactions that occur during the course of solid phasesynthesis. The support material can be a soluble or insoluble polymerhaving a molecular weight of 10,000 up to infinity for crosslinkingpolymers.

Examples of useable pre-existing support materials are described in G.B. Fields et al., Int. J. Peptide Protein Res., 35, 161 (1990) and G. B.Fields et al., in Synthetic Peptides: A User's Guide, G. A. Grant, Ed.,pages 77-183, W.H. Freeman and Co., New York, N.Y. (1992). The supportmaterial is in the form of an organic polymeric material, such aspolystyrenes, polyalkylenes, nylons, polysulfones, polyacrylates,polycarbonates, polyesters, polyimides, polyurethanes, etc. and havinghydroxyl, amino or thiol substituents on the surface. For pre-existingsupport materials, a preferred support material is polystyrene.

A suitable catalyst for the Michael reaction is a base of which theconjugated acid preferably has a pKa between 12 and 14. Most preferablyused bases are organic. Examples of such bases are 1,4-dihydropyridines,methyl diphenylphosphane, methyl di-p-tolylphosphane, 2-allyl-N-alkylimidazolines, tetra-t-butylammonium hydroxide, DBU(1,8-diazabicyclo[5.4.0]undec-7-ene) and DBN(1,5-diazabicyclo[4.3.0]non-5-ene), potassium methoxide, sodiummethoxide, sodium hydroxide, and the like. A highly preferred catalystin connection with this invention are DBU and tetramethylguanidine. Theamount of catalyst used in a curable composition in accordance with thepresent invention is preferably between 0.05% by weight and 2% by weightmore preferably between 0.1% by weight and 0.6% by weight.

Preferably, a curable composition in connection with the presentinvention is prepared by mixing two parts together. One part containsthe catalyst and the other contains the reactants, i.e. the polyacrylcomponent, the Michael donor component, and the monomer having areactive functional group. Although it is also possible to have thecatalyst together with one of the reactants in one part and having theother reactant in the other part, these embodiments generally produceinferior results, presumably because reaction of the catalyst with thereactant can take place. The extent of this reaction will generallydepend on the kind of catalyst and reactants used.

The stoichiometry of the reactants is based not on molar amounts of thecomponents, but molar functional group equivalents. For example, acompound of formula I such as methylacetoacetate has two protons alphato both of the carbonyl groups, and so can react with two acryl groups.Thus methylacetoacetate has two functional group equivalents. Ingeneral, the ratio of Michael donor functional group equivalents (“donorequivalents”) to Michael acceptor functional group equivalents(“acceptor equivalents”) is less than 2:1, more preferably less than1.5:1 and most preferably less than 1.1:1.

The amount of unsaturated monomer having an azlactone (or ring-openedazlactone) reactive functional group is generally less than or equal tothe difference between the amount of Michael donor functional groupequivalents to Michael acceptor functional group equivalents. Mostpreferably, donor equivalents≧acceptor equivalents+azlactone monomer.For example where the ratio of donor equivalents to acceptor equivalentsis less than 2:1, the amount of azlactone monomer is 2 equivalents orless. Where the ratio of donor equivalents to acceptor equivalents isless than 1.5:1, the amount of azlactone monomer is 1 equivalent orless. Where the ratio of donor equivalents to acceptor equivalents isless than 1.1:1, the amount of azlactone monomer is 0.2 equivalents orless.

The telechelic polymers produced may be represented by the formula:

wherein Az is the residue of an azlactone (or ring-opened azlactone)monomer,

D is the residue of a Michael donor component (such as represented byformulas I, II or III), A is the residue of a polyacryl component, and yis at least 1. It will be understood that the above formula representsthe most simple case where each of the donor and acceptor components hastwo functional equivalents.

More complex structures where the donor or acceptor component have afunctional equivalent of more than two may also be produced and arewithin the scope of the invention. For example, where the polyacrylcomponent A is trivalent, the telechelic polymers include those of theformula:

where D, A, y, and Az are as previously described.

Where D is trivalent, the telechelic polymers include those of theformula:

More particularly, the polymers produced may have the general structure

wherein

W¹ and W² each independently selected from a cyano group, a nitro group,an alkyl carbonyl group, an alkoxy carbonyl group, an aryl carbonylgroup, an aryloxy carbonyl group, an amido group, and a sulphonyl group;R⁴ is a polyvalent organic group; R⁵ is H or a C₁ to C₃ alkyl group;

each R⁶ is independently H, an alkyl group having 1 to 14 carbon atoms,a cycloalkylgroup having 3 to 14 carbon atoms, an aryl group having 5 to 12 ringatoms, an arenylgroup having 6 to 26 carbon and 0 to 3 S, N, and nonperoxidic Oheteroatoms, or R² andr³ taken together with the carbon to which they are attached form acarbocyclic ring containing 4 to 12 ring atoms;n is 0 or 1, and x is at least 1.

Curable compositions according to the present invention may be coated ona substrate and at least partially cured to provide a composite article.Suitable substrates include, for example, glass (e.g., windows andoptical elements such as, for example, lenses and mirrors), ceramic(e.g., ceramic tile), cement, stone, painted surfaces (e.g., automobilebody panels, boat surfaces), metal (e.g., architectural columns), paper(e.g., adhesive release liners), cardboard (e.g., food containers),thermosets, thermoplastics (e.g., polycarbonate, acrylics, polyolefins,polyurethanes, polyesters, polyamides, polyimides, phenolic resins,cellulose diacetate, cellulose triacetate, polystyrene, andstyrene-acrylonitrile copolymers), and combinations thereof. Thesubstrate may be a film, sheet, or it may have some other form.

The curable composition may be applied to the substrate by conventionaltechniques such as, for example, spraying, knife coating, notch coating,reverse roll coating, gravure coating, dip coating, bar coating, floodcoating, or spin coating. Typically, the curable composition is appliedto the substrate as a relatively thin layer resulting in a dried curedlayer having a thickness in a range of from about 40 nm to about 60 nm,although thinner and thicker (e.g., having a thickness up to 100micrometers or more) layers may also be used. Next, any optional solventis typically at least partially removed (e.g., using a forced air oven),and the polymerizable composition is then at least partially polymerized(i.e., cured) to form a durable coating, for example, as describedhereinabove.

EXAMPLES

These examples are merely for illustrative purposes only and are notmeant to be limiting on the scope of the appended claims. All parts,percentages, ratios, etc. in the examples and the rest of thespecification are by weight, unless noted otherwise. Solvents and otherreagents used were obtained from Aldrich Chemical Company; Milwaukee,Wis. unless otherwise noted.

Table of Abbreviations Abbreviation or Trade Designation DescriptionHDDA 1,6-hexanediol diacrylate DBU 1,8-diazabicyclo[5.4.0]undec-7-ene2-EHA AcAc 3-Oxo-butyric acid 2-ethyl-hexyl ester Methacrylate3-Oxo-butyric acid ethyl methacrylate ester AcAc VDM2-vinyl-4,4-dimethyl azlactone commercially available from SNPE,Tolouse, France

Examples 1-6 Synthesis of Multimethacrylate Functional TelechelicOligomers

Reaction mixtures containing the reagents shown in Table 1 were placedin glass reaction vessels, sealed, and placed in a water shaker bath at60° C. for 17 hours. The compositions and molecular weights asdetermined by gel permeation chromatography of the oligomers synthesizedare shown in Table 1. Each of the azlactone terminated telechelicpolymers may be converted to a ring-opened azlactone terminatedtelechelic polymer by the methods described herein.

TABLE 1 Methacrylate Di/Mono AcAc HDDA VDM DBU acrylate Mw × Mn ×Example (grams) (grams) (grams) (grams) ratio 10³ 10³ 1 2.5 2.64 0.02572.1 4.7 2 2.5 2.38 0.17 0.025 90/10 20.9 3.4 3 2.5 2.11 0.32 0.02580/20 7.6 2.2 4 2.5 1.85 0.49 0.025 70/30 1.3 0.8 5 2.5 1.59 0.65 0.02560/40 1.3 0.7 6 2.5 1.32 0.81 0.025 50/50 1.4 0.8

1. A polymer of the formula:

wherein Az is the residue of an ethylenically unsaturated monomer havingan azlactone functional group, D is the residue of a Michael donorcomponent, A is the residue of a polyacryl component, and y is atleast
 1. 2. The polymer of claim 1 wherein Az is

wherein R⁵ is H or a C₁ to C₃ alkyl group; each R⁶ is independently H,an alkyl group, a cycloalkyl group, an aryl group, an arenyl group, orthe geminal R⁶ groups form a carbocyclic ring; and n is 0 or
 1. 3. Thepolymer of claim 1 of the formula:

wherein W¹ and W² each independently selected from a cyano group, anitro group, an alkyl carbonyl group, an alkoxy carbonyl group, an arylcarbonyl group, an aryloxy carbonyl group, an amido group, and asulphonyl group; R⁴ is a polyvalent organic group; R⁵ is H or a C₁ to C₃alkyl group; each R⁶ is independently H, an alkyl group having 1 to 14carbon atoms, a cycloalkyl group having 3 to 14 carbon atoms, an arylgroup having 5 to 12 ring atoms, an arenyl group having 6 to 26 carbonand 0 to 3 S, N, and nonperoxidic O heteroatoms, or R² and R³ takentogether with the carbon to which they are attached form a carbocyclicring containing 4 to 12 ring atoms; Z is —O—, —S—, or —NR wherein R⁸ canbe a H, an alkyl, a cycloalkyl or aryl, a heterocyclic group, an arenyl;n is 0 or 1, and x is at least
 1. 4. The polymer of claim 1 of theformula:

wherein R² and R³; each independently represent an aryloxy group, analkoxy group, an alkyl group or an aryl group; R⁴ is a polyvalentorganic group; R⁵ is H or a C₁ to C₃ alkyl group; each R⁶ isindependently H, an alkyl group, a cycloalkyl group, an aryl group, anarenyl group, or the geminal R⁶ form a carbocyclic ring containing 4 to12 ring atoms; Z is —O—, —S—, or —NR wherein R⁸ can be a H, an alkyl, acycloalkyl or aryl, a heterocyclic group, an arenyl; n is 0 or 1; and xis at least
 1. 5. The polymer of claim 4 wherein each R² is an alkylgroup and each R³ is an alkoxy group.
 6. The polymer of claim 4 whereinR⁴ is the residue of a polyol.
 7. The composition of claim 1 wherein theratio of donor equivalents to acceptor equivalents is less than 2:1. 8.The composition of claim 1 wherein the ratio of donor equivalents toacceptor equivalents is less than 1.5:1.
 9. The composition of claim 1wherein the ratio of donor equivalents to acceptor equivalents is lessthan 1.1:1.
 10. The composition of claim 1 wherein the molar amount ofdonor equivalents≧acceptor equivalents+azlactone monomer.
 11. A methodfor preparing a telechelic polymer comprising combining a basic catalystwith a curable composition comprising: a) a Michael donor component; b)a polyacryl Michael acceptor component; and c) an ethylenicallyunsaturated monomer having an azlactone functional group.
 12. The methodof claim 11 wherein the catalyst is used in amounts of 0.05% to 2% byweigh.
 13. The method of claim 11 wherein said Michael donor componentcorresponds to one of formulas (I), (II) or (III):(W¹—CHR¹—C(O))_(x)—P  (I)(W¹—NH—C(O))_(n)—P  (II)W¹—CH₂—W²  (III) wherein R¹ represents hydrogen, an alkyl group or anaryl group; W¹ and W² each independently selected from a cyano group, anitro group, an alkyl carbonyl group, an alkoxy carbonyl group, an arylcarbonyl group, an aryloxy carbonyl group, an amido group, and asulphonyl group; P represents a mono- or multi-valent organic residue,or the reaction residue of a polyol or polyamine in an acetoacetylationreaction, and x is an integer of 1 or more, with the proviso that thenumber of donor equivalents is two or greater.
 14. The method of claim11 wherein said Michael donor is of the formula:R²—CO—CH₂—CO—R; wherein R² and R³; are independently selected from asubstituted or an unsubstituted alkyl, an unsubstituted or substitutedaryl, a substituted or unsubstituted alkoxy group or a substituted orunsubstituted aryloxy group.
 15. The method of claim 14 wherein theMichael donor component is selected from acetylacetone,methylacetoacetate, ethylacetoacetate, methyl malonate, ethyl malonate,t-butyl acetoacetate.
 16. The method of claim 11, wherein said polyacrylcomponent is of the formula:R⁴-(Z-C(═O)—CH═CH₂)_(z) wherein each Z independently represents —S—,—O—, —NH—, or —NR⁵—, where R⁵ is H, or an alkyl group having from 1 to 6carbon atoms; R⁴ independently represents a polyvalent organic grouphaving a valence of z.
 17. The method of claim 11 wherein saidethylenically unsaturated monomer having a azlactone functional group isof the formula:

where R⁵ is H or an C₁ to C₃ alkyl group; each R⁶ is independently H, analkyl group, a cycloalkyl group, an aryl group, an arenyl group, or thegeminal R⁶ groups form a carbocyclic ring; and n is 0 or 1.